การรวมและเรียงลำดับผลลัพธ์ด้วย sort, uniq และ cut

Filtering with grep and editing with sed/awk gets you far, but real pipelines often need to reorder, deduplicate, and slice columns of text.

• sort orders lines
• uniq collapses duplicates
• cut extracts fields

Together they turn raw streams into clean summaries.

sort reads lines and prints them in lexical order by default. It works great inside a pipe.

Use -n for numeric order and -r to reverse. Without -n, 10 sorts before 2.

-k picks the column to sort on and -t sets the delimiter. Here we sort a CSV by the second field numerically.

uniq only collapses adjacent duplicate lines, so you almost always sort first.

uniq -c prefixes each line with how many times it appeared. This is the classic frequency-count idiom.

Combine the tools to build a leaderboard: count, then sort the counts descending.

cut -d sets the delimiter and -f selects fields. Here we grab the username column from a colon-separated record.

cut -c selects character ranges instead of fields, useful for fixed-width data.

uniq -u prints lines that appear exactly once; uniq -d prints only those that repeat.

Put it all together: extract a field, sort it, count duplicates, and rank. This pattern answers questions like which IP hit us most?

You can now reshape text streams end to end:

• sort (with -n, -r, -k, -t) orders lines
• uniq (with -c, -d, -u) deduplicates and counts
• cut (with -d/-f or -c) extracts fields

The cut | sort | uniq -c | sort -nr chain is one of the most useful one-liners in Linux.